>This would cause serious problems later, but the senators profiting neither knew nor cared. //

Strikes me that this is about comparative level of development. As long as large inequalities exist then richer countries can feed off the labour of less developed countries. When those countries develop sufficiently they can't be [ab]used in that way.

This is a big issue in UK at the moment as we've kicked out loud of foreign workers, and now have harvest locally produced food, in part because farmers won't pay wages at UK subsistence levels.